RU2284479C2 - Restriction device for metering gas flow rate - Google Patents

Abstract

FIELD: oil and gas industries.

SUBSTANCE: invention can be used for metering flow rate of gas transported along pipelines. Proposed restriction device contains housing with holes to tap gas pressure and central hole. Housing is provided with slot whose upper part is made closed. Open part of slot is arranged in lower part of housing. Holder carrying diaphragm with calibrated hole is installed in slot. Diaphragm is secured in holder by U-shaped seal fitted on diaphragm. Housing is closed from bottom by cover clamped by strap. Detachable mechanism installed in lower part of housing makes it possible to take out holder with diaphragm.

EFFECT: improved accuracy of metering of gas flow rate, reduced metal usage and increased strength of device.

3 dwg

Description

The invention relates to the field of measuring equipment, and more specifically to diaphragm-type devices for measuring the flow of gas transported through main and technological pipelines in the oil and gas industry.

Known narrowing device for measuring gas flow (see. A. S. of the USSR No. 951075, CL G 01 F 1/34, 1976). The known device comprises a housing with pressure chambers, separated by a removable measuring diaphragm and a transverse slit-like window for removing the diaphragm, a sealing cover, sealing elements and a cover.

The disadvantage of this device is that during operation of the constriction device in the inlet pipe near the diaphragm, various substances contained in natural gas (including tar-forming) accumulate, debris remaining after repair of the pipeline. This leads to a decrease in the cross section of the pipeline, a displacement of the axis of the gas flow, an increase in the gas flow rate in the pipe, an increase in the roughness of the pipe, and, consequently, a decrease in the accuracy of the measurement of gas passing through. Therefore, to restore the original accuracy of the constriction device, regular cleaning is required, which is, firstly, difficult to implement in this design, and secondly, the gas pipeline must be stopped for the cleaning period.

Of the known narrowing devices for measuring gas flow, the closest in technical essence is the device described in the patent of the Russian Federation No. 2129701, class. G 01 F 1/42, 1997

This narrowing device for measuring gas flow contains a housing with holes for sampling the gas pressure and a central hole for transporting gas, made with a through groove in which a holder is mounted that carries a diaphragm with a calibrated hole. Above and below the casing is closed with covers. The lid presses on top of the lid. In the lower part of the housing there are drain holes. The holder with the diaphragm is removed by means of a rack and pinion transmission. The diaphragm is mounted in the holder through an O-ring seal.

The disadvantage of this device is that the groove for the holder with a diaphragm is made through. The upper window of the groove is designed to remove the diaphragm holder, and the lower one to clean the pipeline from solid deposits. The presence of an additional window in the lower part of the device requires an additional cover with a seal, and this, in turn, leads to the fact that, firstly, the device becomes less reliable during operation and more dangerous, since gas leaks through the additional cover are possible secondly, the productivity of the pipeline decreases, since additional time is required to service the device, because the bottom cover must be removed during each maintenance, and then installed and sealed; thirdly, the device novitsya more metal as the body with a through slot less rigid and durable when dealing with the pressure.

The objective of the present invention is to provide a constricting device, which allows to increase the accuracy of measuring the gas flow, to reduce the time for servicing the device.

This object is achieved in that in a constricting device for measuring gas flow, comprising a housing closed with a cover with openings for taking gas pressure and a central opening for transporting gas, a holder with a diaphragm installed in the groove of the body, a mechanism for removing a holder with a diaphragm from the housing and seals, according to the invention, the groove for the holder with a diaphragm in the upper part is closed, and the open part of the groove for the holder with a diaphragm, a cover and a mechanism for removing from the holder of the holder with a diaphragm mine located in the lower part of the body.

Such a constructive implementation of the constricting device for measuring gas flow will increase the accuracy of the selection of pressure and subsequent measurement of gas flow by reducing the additional disturbance of the gas flow at the inlet of the diaphragm from mechanical deposits. Performing a groove under the holder with the diaphragm in the upper part closed will make the case more rigid, durable and less metal-intensive, and performing the open part of the groove in the lower part of the housing will facilitate maintenance and reduce maintenance time, since it is possible to remove the cover from the bottom and simultaneously revision of the diaphragm and clean the device of accumulated solid deposits, which, with significant accumulation, displace the axis of the gas flow relative to the axis of the diaphragm, which reduces the accuracy of measuring gas flow and uet part of the additional centering holder with the diaphragm.

To explain the invention, a specific embodiment of the invention is provided below with reference to the accompanying drawings, in which:

figure 1 shows a narrowing device for measuring gas flow (General view);

figure 2 is a cross section aa in figure 1;

figure 3 is a longitudinal section in figure 1.

The narrowing device for measuring gas flow contains a housing 1 with holes 2, 3 for sampling the gas pressure and a Central hole 4 for transporting gas. The housing 1 has a groove 5, the upper part of which is closed, and the open part of this groove is located in the lower part of the housing 1. In addition, the groove 5 is located in a vertical plane relative to the horizontal axis of the pipeline and can be made either coaxially relative to the vertical axis of this pipeline, or deployed in relation to her. A holder 6 is installed in the groove 5, carrying a diaphragm 7 with a calibrated hole 8. In the lower part, the housing 1 is closed by a cover 9, which is clamped by the bar 10. The holder 6 with the diaphragm 7 is removed by means of a removable extraction mechanism 11 installed in the lower part of the housing 1. The diaphragm 7 is fixed in the holder 6 by means of a U-shaped seal 12, which is worn on the diaphragm 7.

The device operates as follows.

Gas is transported under pressure through a narrowing device mounted in the measuring section of the pipeline and being part of this pipeline. Passing through a calibrated hole 8 of the diaphragm 7, the gas flow receives disturbances that lead to a pressure drop in the gas before and after the diaphragm.

Gas pressure is taken through the hole 2 in front of the diaphragm and the hole 3 located after the diaphragm, and transmitted to the differential pressure gauges and flow meters of the gas measuring station, recording the flow rate of the transported gas.

If necessary, a periodic audit or replacement of the seal 12 and the diaphragm 7, they are removed from the housing 1 together with the holder 6 using the mechanism 11 for extraction. To do this, remove the cover 9, the strap 10 and the mechanism 11 pull out the holder 6 with the diaphragm 7 and the seal 12 from the groove 5 down under the constricting device, where you can inspect the diaphragm and seal 12 and, if necessary, replace. In this case, after removing the cover 9, strap 10 and extending the holder 6, the groove 5 at the bottom opens and dirt accumulated in the pipeline near the diaphragm spills out. That is, during revision of the diaphragm, the pipeline is simultaneously cleaned from accumulations. Installing the holder 6 with the diaphragm 7 in the working position is in the reverse order.

The proposed narrowing device for measuring gas flow in comparison with the known ones allows to increase the accuracy of measuring gas flow by reducing the displacement of the axis of the diaphragm relative to the axis of the gas flow, to increase the productivity of the pipeline by reducing the time for its maintenance and to reduce the metal consumption of the narrowing device.

Claims (1)

Narrowing device for measuring gas flow, comprising a housing closed with a cover with openings for taking gas pressure and a central opening for transporting gas, a holder with a diaphragm installed in the groove of the housing, a mechanism for removing the diaphragm from the holder body and seals, characterized in that the groove for the holder with the diaphragm in the upper part is made closed, and the open part of the groove under the holder with the diaphragm, the cover and the mechanism for removing from the body of the holder with the diaphragm are located in the lower part of the case.

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